Many database systems contain very large amounts of data (often exceeding one or even tens of terabytes) stored on multiple disk arrays and managed by multiple computing systems. Database users usually extract information from these systems using some form of database-query language, typically an industry-standard language, such as the Structured Query Language (SQL), standards for which are defined by the American National Standards Institute (ANSI).
A user generally gains access to a database through a client computer networked to the database system. Database software installed in the client computer recognizes database query commands entered by the user and acts upon these commands. Upon receiving a query command from the user, the client software reads and interprets the command and, in response to the command, asks the database system to gather the requested data, extracts the gathered data from the database, and then receives the data at the client computer.
In general, the data retrieved by the user is displayed as text on a display console, usually in a dedicated window in a window-based operating system, such as Unix or Microsoft Windows 9x, 2000, or NT. The display console often shows the text with some rudimentary formatting, such as in the form of a table representing the relational nature of the data in the database.
For a database system that stores object data, such as video, image, and audio files, the client software retrieves metadata describing the objects requested by the user. The display console displays this metadata as text, which usually gives very little useful information about the requested object. To retrieve and actually display the contents of a requested object, the user must type one or more commands that instruct the client software to retrieve the object and launch an appropriate viewer program, such as an image viewer or a sound player. Alternatively, the user must launch the appropriate viewer program manually and then open the requested object from that program.
Described below are one or more implementations of the invention, including a technique for providing a user-friendly, formatted display of information retrieved from a database, such as the Teradata Object-Relational database system offered by NCR Corporation. The information is displayed in a conventional, well-recognized format, such as Hypertext Markup Language (HTML) or Extensible Markup Language (XML) tables, standards for which are put forth by the World Wide Web Consortium (W3C). This technique also allows quick and easy opening of objects stored in the database, e.g., by storing a copy of the object in the client computer with a file extension indicating the object""s file type. The file extension identifies the type of viewer program needed to view the object.
In one approach, the invention involves delivering information from a database to a user after receiving an instruction from the user to retrieve the information from the database. One or more computing systems, such as a database server, a web server, or a client computer, retrieves the requested information from the database and applies formatting instructions to text extracted from the requested data. In general, the instructions include terms taken from a selected formatting language, such as HTML or XML. Applying the formatting instructions often involves inserting markup-language tags within the text. The computer then displays the text in a format prescribed by the formatting instructions.
In many cases, the computer also displays a hyperlink to an object requested by the user, often using metadata describing the object in creating the hyperlink. Displaying the formatted text and hyperlinks often involves launching a program, such as an off-the-shelf web browser, designed to interpret markup-language tags and format the text accordingly.
Other features and advantages will become apparent from the description and claims that follow.